Protective effects of valsartan administration on doxorubicin‑induced myocardial injury in rats and the role of oxidative stress and NOX2/NOX4 signaling

Role of Oxidative Stress and Inflammation in Doxorubicin-Induced Cardiotoxicity: A Brief Account

Cardiotoxicity is the main side effect of several chemotherapeutic drugs. Doxorubicin (Doxo) is one of the most used anthracyclines in the treatment of many tumors, but the development of acute and chronic cardiotoxicity limits its clinical usefulness. Different studies focused only on the effects of long-term Doxo administration, but recent data show that cardiomyocyte damage is an early event induced by Doxo after a single administration that can be followed by progressive functional decline, leading to overt heart failure. The knowledge of molecular mechanisms involved in the early stage of Doxo-induced cardiotoxicity is of paramount importance to treating and/or preventing it. This review aims to illustrate several mechanisms thought to underlie Doxo-induced cardiotoxicity, such as oxidative and nitrosative stress, inflammation, and mitochondrial dysfunction. Moreover, here we report data from both in vitro and in vivo studies indicating new therapeutic strategies to prevent Doxo-induced cardiotoxicity.

Untargeted metabolic profiling of high-dose methotrexate toxicity shows alteration in betaine metabolism

Cardiotoxicity is a well-established adverse effect of several drugs across multiple therapeutic indications. It is particularly prevalent following anticancer therapy. In order to evaluate the changes in cellular metabolism associated with methotrexate cardiotoxicity, we treated Wistar rats with a single high dose of methotrexate (HDMTX), and after five days, the animals were sacrificed. We then analyzed the cardiotoxicity parameters in serum like Cardiac enzymes(CK-MB, Troponin T, ALP), Inflammatory markers (TNF-α and IL-6), oxidative stress markers (NO, NOX-2), histopathology and cardiac tissue with the goal of identifying a metabolic signature of cardiotoxicity using discovery-based metabolomics. The biochemical parameters for cardiac enzymes, oxidative stress and inflammatory markers showed a significant increase in all three categories in rats treated with HDMTX. These findings were mirrored in the histopathological analysis confirming cardiotoxicity due to HDMTX. The results showed a total of 95 metabolites that were found to be significantly (p < 0.05) modulated: either up- or downregulated in the HDMTX-treated group when compared with the control group. Using integrated pathway analysis we found these metabolites were associated with many important cardiac tissue metabolic pathways, such as the malate aspartate shuttle, taurine and hypotaurine metabolism, betaine metabolism, spermidine biosynthesis, and homocysteine degradation. Among them, L-arginine, homocysteine, and betaine were significantly upregulated, suggesting their possible association with cardiac tissue injury. Overall, we provided evidence for using untargeted metabolomics to identify novel metabolites associated with HDMTX cardiac toxicity.

NOX4 aggravates doxorubicin-induced cardiomyocyte pyroptosis by increasing reactive oxygen species content and activating the NLRP3 inflammasome

Background

Nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX4)-mediated reactive oxygen species (ROS) has been reported to induce cardiomyocyte apoptosis, but its effect on pyroptosis of cardiomyocytes has been rarely reported. This paper aimed to explore the effects of NOX4-mediated ROS production on doxorubicin (DOX)-induced myocardial injury and pyroptosis through nucleotide-binding and oligomerization domain-like receptor protein 3 (NLRP3) inflammasome.

Methods

HL-1 cells were treated with DOX or mice (30 mice were divided into five groups with six mice/group) underwent intraperitoneal injection with DOX (5 mg/kg, once a week, five times) to induce myocardial injury, followed by assessment of NOX4 and NLRP3 expression in cell supernatant and myocardial tissues. In cardiomyocyte HL-1 cells, cell proliferation was tested by MTT assay and the activity of ROS by probes. The superoxide dismutase (SOD) activity, malondialdehyde (MDA) content, and glutathione (GSH) activity were evaluated by kits. The expression of pyroptosis proteins was assessed by western blotting. Subsequently, the expression of NOX4 or NLRP3 was altered to determine the effect of NOX4 or NLRP3 expression on cardiomyocyte injury and pyroptosis. The animal models were utilized to evaluate the changes in the cardiac function of mice using an echocardiographic system, with these parameters measured including left ventricular ejection fraction (LVEF), left ventricular fractional shortening (LVFS), and left ventricular end-diastolic diameter (LVEDD). Furthermore, the content of myocardial injury markers and the protein expression of pyroptosis proteins were determined to evaluate myocardial injury in the mice.

Results

DOX treatment led to cardiomyocyte injury and pyroptosis, as evidenced by weakened LVEF, LVFS, and cell proliferation (P<0.05), elevated LVEDD, ROS, and MDA (P<0.05), increased expression of pyroptosis proteins (P<0.05), and decreased SOD and GSH (P<0.05). Additionally, NOX4 and NLRP3 were highly-expressed (P<0.05) in cell supernatant and myocardial tissues. In DOX-induced HL-1 cells, the overexpression of NOX4 intensified ROS levels to aggravate cardiomyocyte injury and pyroptosis, which was reversed by treatment of the ROS scavenger N-acetyl-cysteine. Furthermore, it was revealed that the combination of short hairpin RNA (sh)-NOX4 and overexpressed (oe)-NLRP3 reversed the cardioprotective effects of sh-NOX4 and increased myocardial tissue or cell injury and pyroptosis in vitro and in vivo. No mice died during the animal experiments, and only two were ruled out due to a weight loss greater than 20%.

Conclusions

NOX4-mediated ROS production activated NLRP3 inflammasome, thereby aggravating DOX-induced myocardial injury in vitro and in vivo.

Effects of piperlonguminine on lung injury in severe acute pancreatitis <em>via</em> the TLR4/NF-κB pathway

Acute pancreatitis is an inflammatory response in the pancreas, involving activation of pancreatic enzymes. Severe acute pancreatitis (SAP) often causes systemic complications that affect distant organs, including the lungs. The aim of this study was to explore the therapeutic potential of piperlonguminine on SAP-induced lung injury in rat models. Acute pancreatitis was induced in rats by repetitive injections with 4% sodium taurocholate. Histological examination and biochemical assays were used to assess the severity of lung injury, including tissue damage, and levels of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 2 (NOX2), nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 4 (NOX4), reactive oxygen species (ROS), and inflammatory cytokines. We found that piperlonguminine significantly ameliorated pulmonary architectural distortion, hemorrhage, interstitial edema, and alveolar thickening in rats with SAP. In addition, NOX2, NOX4, ROS, and inflammatory cytokine levels in pulmonary tissues were notably decreased in piperlonguminine-treated rats. Piperlonguminine also attenuated the expression levels of toll-like receptor 4 (TLR4) and nuclear factor-kappa B (NF-κB). Together, our findings demonstrate for the first time that piperlonguminine can ameliorate acute pancreatitis-induced lung injury via inhibitory modulation of inflammatory responses by suppression of the TLR4/NF-κB signaling pathway.

Role of oxidative stress and inflammation-related signaling pathways in doxorubicin-induced cardiomyopathy

Doxorubicin (DOX) is a powerful and commonly used chemotherapeutic drug, used alone or in combination in a variety of cancers, while it has been found to cause serious cardiac side effects in clinical application. More and more researchers are trying to explore the molecular mechanisms of DOX-induced cardiomyopathy (DIC), in which oxidative stress and inflammation are considered to play a significant role. This review summarizes signaling pathways related to oxidative stress and inflammation in DIC and compounds that exert cardioprotective effects by acting on relevant signaling pathways, including the role of Nrf2/Keap1/ARE, Sirt1/p66Shc, Sirt1/PPAR/PGC-1α signaling pathways and NOS, NOX, Fe²⁺ signaling in oxidative stress, as well as the role of NLRP3/caspase-1/GSDMD, HMGB1/TLR4/MAPKs/NF-κB, mTOR/TFEB/NF-κB pathways in DOX-induced inflammation. Hence, we attempt to explain the mechanisms of DIC in terms of oxidative stress and inflammation, and to provide a theoretical basis or new idea for further drug research on reducing DIC. Video Abstract.

Decreased Cardiac NOX4 and SIRT-1 Protein Levels Contribute to Decreased Angiogenesis in the Heart of Diabetic Rats: Rescue Effects of IGF-1 and Exercise

Purpose: Reduced angiogenesis in the heart tissue is a primary risk factor for heart disease in the diabetes condition. This study was aimed to evaluate the changes of two main angiogenesis mediators, NADPH oxidase 4 (NOX4) and sirtuin 1 (SIRT-1) protein levels in the heart of diabetic rats and the impact of Insulin-like growth factor 1 (IGF-1) and exercise on these proteins. Methods: Injection of 60 mg/kg of streptozotocin in 40 male Wistar rats led to the induction of type 1 diabetes. Angiogenesis was detected in the hearts by immunostaining for PECAM-1/ CD31 after 30 days of treatment with IGF-1 (2 mg/kg/day) and exercise. ELISA technique was utilized to establish the expression levels of NOX4 and SIRT-1 within the heart. Results: The results revealed a significant increase in HbA1c and a significant decrease in SIRT1, NOX4 levels and angiogenesis grade in the heart of diabetes group compared to control group. Meanwhile, IGF-1 and exercise alone or in combination completely masked these effects. Additionally, synergistic effect on SIRT-1, HbA1c levels and angiogenesis grade is evident when IGF-1 and exercise are applied simultaneously. Conclusion: Our findings suggest that reduction in angiogenesis in the heart of diabetic rats may be mediated by down expression of NOX4 and SIRT-1 protein levels. It was also displayed that IGF-1 and exercise as novel therapies increase NOX4 and SIRT-1 protein levels within the hearts of diabetic rats.

Setanaxib (GKT137831) Ameliorates Doxorubicin-Induced Cardiotoxicity by Inhibiting the NOX1/NOX4/Reactive Oxygen Species/MAPK Pathway

Background: Doxorubicin (DOX)-induced cardiotoxicity is a highly concerning issue, and the mechanism by which DOX induces cardiotoxicity is likely to be multifactorial. NADPH oxidase (NOX) is associated with DOX-induced cardiotoxicity. Setanaxib (GKT137831), a preferential direct inhibitor of NOX1 and NOX4, can delay or prevent the progression of many cardiovascular disorders by inhibiting reactive oxygen species (ROS) generation. In this study, we investigated the role of GKT137831 in ameliorating DOX-induced cardiotoxicity and the potential mechanisms of its action.

Methods and Results: The mice model of cardiotoxicity induced by DOX was established, and GKT137831 treatment was performed at the same time. Neonatal rat cardiomyocytes (NRCMs) were treated with DOX or GKT137831 for in vitro experiments. We found that DOX administration impaired cardiac function in vivo, reflected by decreased left ventricular ejection fraction (LVEF) and fractional shortening (FS%). DOX also impaired the viability of NRCMs in vitro. In addition, DOX increased the levels of NOX1 and NOX4 expression and ROS production and the cardiomyocyte apoptosis rate, both in vivo and in vitro. GKT137831 improved cardiac function, as indicated by the increased LVEF and FS%. In vitro, GKT137831 improved NRCM viability. It also decreased ROS production and the cardiomyocyte apoptosis rate. Apoptotic indices, such as cleaved PARP (c-PARP), cleaved caspase 3 (CC3) and BAX expression levels, were decreased, and the antiapoptotic index of Bcl-2 expression was increased. DOX markedly activated phosphorylated JNK, ERK and p38 proteins in NRCMs. Specific inhibitors of JNK (SP600125), ERK (PD98059) or p38 (SB203580) inhibited DOX-induced apoptosis of NRCMs. GKT137831 pretreatment inhibited excessive DOX-induced MAPK pathway activation.

Conclusion: This study revealed that GKT137831 can alleviate DOX-induced cardiomyocyte apoptosis by inhibiting NOX1/4-driven ROS production. The upregulation of MAPK pathway induced by NOX1/4-derived ROS production may be the potential mechanism of GKT137831 action. GKT137831 may be a potential drug candidate to ameliorate DOX-induced cardiotoxicity.

LCZ696 ameliorates doxorubicin-induced cardiomyocyte toxicity in rats

Doxorubicin (DOX)-based chemotherapy induces cardiotoxicity, which is considered the main bottleneck for its clinical application. In this study, we investigated the potential benefit of LCZ696, an angiotensin receptor-neprilysin inhibitor against DOX-induced cardiotoxicity in rats and H9c2 cells and determined whether the mechanism underlying any such effects involves its antioxidant activity. Male Sprague-Dawley rats were randomly separated into four groups, each consisting of 15 rats (DOX (1.5 mg/kg/day intraperitoneally for 10 days followed by non-treatment for 8 days); DOX + valsartan (31 mg/kg/day by gavage from day 1 to day 18); DOX + LCZ696 (68 mg/kg/day by gavage from day 1 to day 18); and control (saline intraperitoneally for 10 days). DOX-induced elevation of cardiac troponin T levels on day 18 was significantly reduced by LCZ696, but not valsartan. The DOX-induced increase in myocardial reactive oxygen species (ROS) levels determined using dihydroethidium was significantly ameliorated by LCZ696, but not valsartan, and was accompanied by the suppression of DOX-induced increase in p47phox. LCZ696 recovered the DOX-induced decrease in phosphorylation of adenosine monophosphate-activated protein kinase and increased the ratio of Bax and Bcl-2. In H9c2 cardiomyocytes, LCZ696 reduced DOX-induced mitochondrial ROS generation and improved cell viability more than valsartan. Our findings indicated that LCZ696 ameliorated DOX-induced cardiotoxicity in rat hearts in vivo and in vitro, possibly by mediating a decrease in oxidative stress.

Reactive Oxygen Species Induced Pathways in Heart Failure Pathogenesis and Potential Therapeutic Strategies

With respect to structural and functional cardiac disorders, heart failure (HF) is divided into HF with reduced ejection fraction (HFrEF) and HF with preserved ejection fraction (HFpEF). Oxidative stress contributes to the development of both HFrEF and HFpEF. Identification of a broad spectrum of reactive oxygen species (ROS)-induced pathways in preclinical models has provided new insights about the importance of ROS in HFrEF and HFpEF development. While current treatment strategies mostly concern neuroendocrine inhibition, recent data on ROS-induced metabolic pathways in cardiomyocytes may offer additional treatment strategies and targets for both of the HF forms. The purpose of this article is to summarize the results achieved in the fields of: (1) ROS importance in HFrEF and HFpEF pathophysiology, and (2) treatments for inhibiting ROS-induced pathways in HFrEF and HFpEF patients. ROS-producing pathways in cardiomyocytes, ROS-activated pathways in different HF forms, and treatment options to inhibit their action are also discussed.

Cardiac inflammation and fibrosis following chemo/radiation therapy: mechanisms and therapeutic agents

The incidence of cardiovascular disorders is one of the most concerns among people who underwent cancer therapy. The heart side effects of cancer therapy may occur during treatment to some years after the end of treatment. Some epidemiological studies confirm that heart diseases are one of the most common reasons for mortality among patients that were received treatment for cancer. Experimental studies and also clinical investigations indicate that inflammatory changes such as pericarditis, myocarditis, and also fibrosis are key mechanisms of cardiac diseases following chemotherapy/radiotherapy. It seems that chronic oxidative stress, massive cell death, and chronic overproduction of pro-inflammatory and pro-fibrosis cytokines are the key mechanisms of cardiovascular diseases following cancer therapy. Furthermore, infiltration of inflammatory cells and upregulation of some enzymes such as NADPH Oxidases are a hallmark of heart diseases after cancer therapy. In the current review, we aim to explain how radiation or chemotherapy can induce inflammatory and fibrosis-related diseases in the heart. We will explain the cellular and molecular mechanisms of cardiac inflammation and fibrosis following chemo/radiation therapy, and then review some adjuvants to reduce the risk of inflammation and fibrosis in the heart.